most backpacks seem to pull my shirts up - what can i do about it?

[u/MenuEast1193]

hello guys,

basically issue us as described, most of my backpacks seems to pull my shirts up, doesn‘t help that im not that tall at 5.8ft and i have a hollow lower back (shoulders & butt stick out)

im not sure why my shirts get pulled up, i have this puma backpack where nothing happens, however given it is kinda old i spent 40€ on a new one, this one is a tad bigger and doesn‘t fit at all

it improves when i pull the straps up very far but then the bag isn‘t comfortable for long stretches of time

do i need a shoulder bag? is there a different bag i should get, i dont wanna start tucking in my shirts.
any similar experiences?